chr-tutorial-final-PPDP06
ConstraintHandlingRules-TheStorySoFarThomFruhwirth¨UniversityofUlm,Germanywww.informatik.uni-ulm.de/pm/mitarbeiter/fruehwirth/Abstract related. Other influences were the chemical abstract machine [4],termrewritingsystems,and,ofcourse,productionrulesystems.Rule based programming experiences renaissance due to its appli CHR is appealing for computational logic, because logicalcations in areas such as Business Rules, Semantic Web, Computa theories are usually specified by implications and logical equiva tionalBiology,VerificationandSecurity.Executablerulesareusedlences, corresponding to propagation and simplificiation rules. Onin declarative programming languages, in program transformationthe meta level, given the transformation rules for deduction in aand analysis, and for reasoning in artificial intelligence applica calculus,inferencerulesmaptopropagationrulesandreplacementtions.rulestosimplificationrules.Constraint Handling Rules (CHR) [6, 8, 11] is a concurrentTheuseofCHRasageneralpurposeprogramminglanguagecommitted choice constraint logic programming language consist is justified by the following observation: Given a state transitioning of guarded rules that transform multi sets of atomic formulassystem, its transition rules can readily be expressed with simplifi (constraints) into simpler ones until exhaustion. CHR was initiallycation rules. In this way, dynamics and changes (e.g., updates) candeveloped for solving constraints, but has matured into a general ...